It is well known that high power electronic assemblies and components are generally provided with an aluminum or copper heat sink for dissipation of waste heat. Similarly, individual integrated circuits are also mounted on aluminum or copper for heat transfer and heat spreading to alleviate hot spots. As electronic device densities continue to increase, more components are packed into smaller areas and management of the waste heat becomes increasingly more important. High temperature can seriously degrade the life of the electronics.
Hitherto, aluminum or copper has been the material of choice for dissipating and spreading heat. Copper has a thermal conductivity of 380 watts/meter-K which is higher than that of aluminum with a thermal conductivity of 180 watts/meter-K but the density of copper (8.9 gm/cm.sup.3) is over three times that of aluminum (2.7 gm/cm.sup.3). In fact the ratio of thermal conductivity to unit density for copper is 44 as compared to a thermal conductivity ratio for aluminum of 64. Hence, in an application where weight is an important factor aluminum is preferred for use in dissipating heat over that of copper. As electronic items shrink in size, power densities and waste heat become increasing problems and the geometry of the aluminum or copper heat dissipator becomes a limiting factor. For effective heat transfer with aluminum the dissipator will need to be very large whereas for effective heat transfer with copper both weight and geometry considerations prevail. The geometry of the heat dissipator must fit into the space left after the packing of the device is optimized. This necessitates using a dissipator of a versatile formable shape. Materials which have been developed to date as heat dissipating substitutes for copper or aluminum all suffer from low thermal conductivity, high density or rigid geometric design criteria.